Network Rail earthworks condition assessment, UK

Opportunity

Today, Network Rail has responsibility for nearly 200,000 embankments and cuttings, which can pose a significant geotechnical risk, particularly during periods of extreme weather.

“Failures are a regular occurrence,” explained Chris Power, principal engineering geologist with Mott MacDonald. “The vast majority of these earthworks were constructed over 150 years ago, before the development of modern engineering practice.”

Solution

His team has played an instrumental role in developing an integrated set of policies, procedures, standards and tools to allow Network Rail to plan for the maintenance and renewal of their earthworks now, and into the future. “This body of work has stood up to regulatory scrutiny, and it allows the performance of the assets to be measured, relative to the investment made into their condition,” he added.

To date, the work has included:

• Development and implementation of statistically derived hazard identification algorithms, validated against our detailed engineering knowledge
• Ground-breaking research and development into global stability assessment and resilience measurement
• Determination of evidence-based degradation profiles for embankments and cuttings
• Development of strategic, and tactical decision support tools (including a whole life cost model)
• Authoring and implementing asset management policies, and key Network Rail standards to support the policies
• Assurance of bottom-up engineering work banks, to assess their alignment to the overarching policies

Outcome

Our work has allowed Network Rail to more precisely focus their investment in the earthwork assets to reduce both the likelihood and consequence of earthworks failures, and ultimately derailments.